48 votes
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Does COVID-19 have a case fatality rate of 41%? Is this formula correct?

The definition of mortality rate that you've given does not match any practical definition I'm familiar with.* When people talk about the mortality rate of a disease, what they usually mean is the ...
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36 votes
Accepted

Why is the rate of circulating vaccine-derived poliovirus disease booming?

The short version is that in 2016 the polio vaccine changed. A more thorough explanation requires some background on the immunology of polio and its vaccines, which is not straightforward. Polio virus ...
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  • 476
33 votes

Father gets chickenpox, but doesn't infect his two children. How is this possible?

If there was close contact, if the 90% rate is accurate, and if occurrence is independent in related individuals, then you would expect 0.10 * 0.10 = 1% of contacts with 2 potentially vulnerable ...
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20 votes

Does COVID-19 have a case fatality rate of 41%? Is this formula correct?

The equation you use for mortality is only really useful in the very long term for a known disease, when most cases have resolved. It's not very informative in the short-term, when the vast majority ...
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  • 12k
19 votes
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A cheap and easy inactivated vaccine for COVID-19

The only approved inhaled vaccine is the flu vaccine delivered intra-nasally. It uses a live attenuated virus. There are a whole list of people who should not receive it because it's a live virus, ...
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15 votes
Accepted

If a SARS-CoV-2 asymptomatic infected individual is exposed to a high viral load, could they develop COVID-19 disease?

What your government is proposing is a lot less than what was actually done in China. There, and perhaps that is still the case, large numbers of asymptomatic infected people were housed together in ...
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14 votes
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Father gets chickenpox, but doesn't infect his two children. How is this possible?

To add to @BryanKrause's answer re: rare events happen all the time, the children are not out of the woods yet. The mean incubation time for a primary VZV infection (the clinical syndrome known as ...
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  • 3,153
14 votes

Does COVID-19 have a case fatality rate of 41%? Is this formula correct?

I'd like to chime in with an explanation of what exactly is wrong with the calculation offered in the question, rather than just saying "it's a wrong formula". Understanding the "whys" of the fallacy ...
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  • 241
12 votes
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Laptops in the dark and miscalculating bats: how dangerous is that for rabies?

This event occurred in the US. In the US, enzootic (dog-to-dog) canine rabies virus has been virtually eliminated through vaccination and stray control programs, making wild animals the primary ...
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8 votes

Father gets chickenpox, but doesn't infect his two children. How is this possible?

Apart from not getting infected due to pure chance (as mentioned already) there is one highly probable explanation (explanation, not overall chance). People get, but don't show it: asymptomatic ...
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8 votes
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Is there evidence that the over-avoidance of germs weakens our immune system?

The hygiene hypothesis For some reason I hold the opinion that the immune system needs to be kept busy so it wont get weak In scientific terms, this is known as the hygiene hypothesis. It was ...
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  • 6,998
7 votes

I have natural immunity to Hepatitis B. Do I pose risk to others?

The Hepatitis B core antibody test is positive for IgG but negative for IgM indicating that you had the hepatitis B infection a while ago. The negative hepatitis B surface antigen test means that they ...
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  • 13.2k
7 votes
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Can the Coronavirus be spread via public toilet seats?

The virus causing COVID-19 infects the respiratory tract. It is spread in droplets of moisture when an infected person sneezes, coughs, and exhales. These droplets can be inhaled directly and can also ...
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6 votes

Is there scientific evidence that spacing out vaccines have any positive effects?

There is evidence that delaying or refusing immunization puts children at risk of disease here and here. There is also evidence that delaying or spreading out MMR or MMRV in particular puts children ...
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  • 3,153
5 votes
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What diseases can be spread by mosquitos?

Mosquitos transmit the pathogens that cause malaria, filariasis, dengue, yellow fever, West Nile fever, Rift Valley fever, and dozens of other infectious diseases of humans, domestic animals, and ...
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  • 6,998
5 votes
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Should I be worried about rat bite

Yes. There are a number of diseases that can be transmitted by rodents, and several of them can be quite serious. This is the list of diseases that can be directly transmitted by rodents according to ...
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5 votes

Laptops in the dark and miscalculating bats: how dangerous is that for rabies?

According to the CDC (Center for Disease Control). Rabies is transmitted via saliva of infected mammals, bats in your case. You state that you were not bitten, and did not feel any type of liquid on ...
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  • 110
5 votes

Can ingesting a mosquito make you sick?

Positively, no. HIV is not spread by mosquitoes. You cannot contract any disease from swallowing a mosquito. Here, is a very large list of all the things that you could have caught :) If you ...
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5 votes

Are motorcycle helmets effective in preventing Corona?

It's better to use some guidelines from reputable sources rather than coming up with your own. The WHO does not recommend masks for healthy people in most circumstances, only when directly dealing ...
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4 votes

Does being infected protect one from further infection?

In general: No. Having ulcers does not protect you from catching the flu. But that "no" is an oversimplification. The devil is indeed in the details. The innate immune system and the ...
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4 votes
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Is E. coli contagious?

Yes, E. coli is definitely contagious through direct contact. In fact your girlfriend's pyelonephritis could have come from you after sexual intercourse. The general mechanism for this would be that ...
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4 votes

Are any infectious diseases 100% fatal?

First a clarification: The Milwaukee Protocol is now considered a failure. As a treatment option it not considered valid option any more. There are vaccines for rabies and port exposure prophylaxis ...
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4 votes
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Are any infectious diseases 100% fatal?

Creutzfeldt-Jakob disease is considered 100 percent fatal. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Creutzfeldt-Jakob-Disease-Fact-Sheet CJD is classified as a ...
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4 votes
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What is daily sedation interruption for ventilated patients?

Yes, daily sedation interruption means a break in giving the sedation therapy. According to a 2014 Cochrane review: Daily sedation interruption versus no daily sedation interruption for critically ...
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4 votes

Does COVID-19 have a case fatality rate of 41%? Is this formula correct?

According to earlier answers, in this early phase of 2019-nCoV, Nd/(Nd+Nr) is an overestimator, and Nd/Nc is an underestimator. Since the currently bantered about rate matches the underwestimator ...
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4 votes
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Are motorcycle helmets effective in preventing Corona?

I think it's a great idea. It protects your eyes from respiratory droplets and keeps you from touching your face. I don't know how well it would work from keeping droplet from reaching your mouth, but ...
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4 votes

Does bleach have to be diluted to be more effective to kill virus?

The text does not say that more diluted bleach is more effective at killing viruses (or bacteria, or yeast, for that matter). I'm quoting: ...A tenfold dilution of bleach, which subsequently mixed ...
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  • 141
4 votes

Does wearing gloves help against being infected with COVID-19?

My research search-fu is rather weak, and it's also quite likely that such research doesn't exist as it's not really how latex (or equivalent) gloves work. The gloves will support infectious agents ...
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  • 167
4 votes
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Does wearing gloves help against being infected with COVID-19?

If you are dealing with an infectious agent transmitted by bodily fluids, HIV or Ebola say, then gloves are an important element of personal protective equipment. Gloves help prevent infectious fluid ...
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